As flu holds steady, CDC urges vigilance, vaccination

Feb 5, 2010 (CIDRAP News) – Pandemic flu activity last week stayed level with the previous week, though the virus continues to circulate and cause deaths, prompting a warning from the US Centers for Disease Control and Prevention (CDC) that Americans shouldn't let their guard down.

The CDC's latest caution about complacency came the same day a survey from Harvard's School of Public Health revealed that 44% of Americans believe the pandemic H1N1 outbreak is over. The Harvard poll, eighth in a series, was conducted by telephone between Jan 20 and 24 and included 1,419 adults.

Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, told reporters at a briefing today that doctor's offices, clinics, pharmacies, and some schools have plenty of vaccine now, making it easy for people to be immunized. "H1N1 vaccination remains a good idea for a very preventable disease," she said. "We are remaining vigilant here, and we should not become complacent."

"Right now we aren't seeing signs of a major increase in H1N1, but we are seeing persistent transmission, including hospitalizations and deaths," she said. "Vaccination is such an easy step to take to reduce the chance that will happen to you or someone you love."

Flu activity near seasonal normCurrent levels of flu activity are similar to what the CDC sees this time of year during a normal flu season, Schuchat said. According to the CDC's flu surveillance report for the week ending Jan 30, no states reported widespread activity, and six reported regional activity, one more than the previous week. States reporting regional activity were Alabama, Georgia, Maine, New Jersey, New Mexico, and Virginia.

Other flu indicators were mixed. Though visits to doctors for flulike illnesses remained below the national baseline, the number for the region that includes Alaska, Oregon, Idaho, and Washington increased slightly from the past week. Deaths from pneumonia and influenza decreased slightly but remained above the national baseline for the third week in a row and higher than the CDC expects for this time of year.

Schuchat said the CDC is looking into reasons for the continuing high levels of pneumonia and influenza deaths. Though many of the fatalities are likely to be from pandemic flu, she noted that other respiratory viruses are circulating now, such as rhinovirus and respiratory syncytial virus.

The CDC said it received nine more reports of pediatric flu deaths. Eight of the patients had lab-confirmed pandemic H1N1 infections and one involved an influenza A virus of undetermined subtype but was probably the pandemic virus. The number was up from five the previous week, but Schuchat said some of the new reports involve deaths that occurred earlier in the flu season.

Very few seasonal flu viruses are circulating, she said. The CDC said testing last week revealed only two isolates that were positive for seasonal strains, and both were influenza B. Yesterday the Iowa Department of Public Health said it had received its first confirmed seasonal flu report, influenza B in a 30-year-old woman with no underlying health conditions.

So far 124 million pandemic vaccine doses have been shipped to states, with millions more to become available, Schuchat said. The CDC is urging parents to ensure that children under age 9 who have received their first dose follow up with the second dose, which is ideally given a month after the first.

CDC refocuses on vaccination targetsAnother group that the CDC is targeting is adults, Schuchat said, pointing to Harvard's latest flu attitudes survey, which found that many seem to be resisting the vaccine for various reasons. Only 37% of adults have received the vaccine or intend to get it, though 53% have gotten or will get their children vaccinated.

Dr Robert Blendon, director of the Harvard Opinion Research Program, said in a press release today that many parents heeded public health messages to vaccinate their children against a virus that hit young people unexpectedly hard. "But there remains a steady core of adults who, regardless of messaging and other efforts, has chosen not to get the H1N1 vaccine. This group’s set of attitudes has proven very difficult for public health officials to change."

Those who said they were unlikely to get the vaccine indicated they didn't think the outbreak was as serious as originally thought (37%), had safety concerns (35%), thought they weren't at risk (30%), or could get medication to treat the flu if they got sick (27%)

The CDC's concerns about complacency appear to be justified by the Harvard group's finding that concern about getting sick from H1N1 during the next 12 months has dropped to 32% from a peak of 52% in September.

"The skepticism of this group indicates that, going forward, it may be difficult to get more movement in the percentage of adults vaccinated for H1N1 or for a similarly behaving new flu virus," said Blendon.

Dr Gillian K. Steel Fisher, a research scientist at the Harvard School of Public Health, said in the press release that three-fourths of the public reported seeing ads since December about the important of pandemic flu vaccination, but many of them aren't responding to the message.

Schuchat said the CDC's own data suggest that the top reason people resist the vaccine is that they don't believe they are at risk. Still, the CDC takes people's concerns about safety very seriously, she said, commenting, "Extensive monitoring of safety continues with excellent results. We think this is a very safe vaccine."

Americans give flu response good marksSome European elected officials have criticized their nation's responses to pandemic influenza and said governments wasted money on surplus flu vaccine doses. However, the Harvard poll suggests that most Americans are pleased with the public health response to the outbreak and the amount of flu vaccine that federal officials ordered.

A majority (59%) rated the overall response to the pandemic H1N1 outbreak as excellent or good, while 39% rated the response as fair or poor. About half said public health officials focused the right amount of attention on the outbreak, but 26% said they spent too much attention and 16% said they spent too little.

More people thought it was important to purchase enough vaccine to rule out any shortage, even if some doses went unused, rather than purchase a more limited supply (59% versus 38%).